Paper coated metal building panel and composite panels using same

ABSTRACT

A building panel  20  is disclosed which is of sandwich construction having metal sheet structures  21, 22  interconnected by a core  23 . The panel  20  includes profiled edge regions  24, 25  enabling the panel to interlock with a like panel. In one form a paper covering  27  is bonded to the metal sheet structure so that panel has a surface characteristic similar to that of plasterboard. A reinforcing element  40  is also disclosed which is arranged to be connected at the joint between abutting panels to improve the load bearing capacity of the panel  20.

This application is a U.S. patent application filed under 35 U.S.C. 371,based on PCT International Application No. PCT/AU99/00264, filed Apr. 9,1999, which claims priority to Australian Patent Application No. PP2898, filed Apr. 9, 1998.

FIELD OF THE INVENTION

The present invention relates to a building panel. One aspect of theinvention has been developed especially, but not exclusively for use ininterior wall or ceiling panelling, and the invention is hereindescribed in that context. However it is to be appreciated that theinvention has broader application and is not limited to these uses. Inparticular, another aspect of the invention is especially suited for usein flooring or the like.

BACKGROUND OF THE INVENTION

In the building industry, panels are widely used in interior walls,partitions and ceilings. One of the most common type of panelling usedis plasterboard, which traditionally is formed from a core of gypsum oranhydrite plaster faced with two sheets of heavy paper. Plasterboard hasgained widespread acceptance because it is inexpensive, relatively lightweight, can be easily cut and provides a good surface finish.

However, there are significant problems with plasterboard. Traditionalplasterboard panels are not self supporting and need to be fixed to asupporting frame such as a stud wall or the like. This substantiallyincreases the cost of installation. Furthermore, plasterboard hasrelatively poor thermal and acoustic insulation properties as comparedto block walls, and is relatively inflexible thereby making it difficultto form into complex shapes.

Various proposals have been made to address these problems. Theseinclude the development of hollow core reinforced plaster panels orprefabricated sandwich panels made from two sheets of plasterboardbonded to a paper honeycomb core. Whist such designs are selfsupporting, they have limited applications and have not gainedwidespread acceptance.

SUMMARY OF THE INVENTION

An aim of a first aspect of the present invention is to provide abuilding panel which is similar to traditional plasterboard panels inboth terms of its costs and surface characteristics, yet which is ableto provide significant improvements in respect of its structuralproperties.

According to this aspect of the present invention, there is provided abuilding panel including a metal sheet substrate and a paper coveringbonded to said substrate, wherein said paper covered metal sheet forms amajor surface of the panel and wherein said metal sheet includesopposite edges which are shaped to form edge regions of the panel, eachedge region being formed to include a connecting element which extendsalong that edge region and which allows for interconnection of the panelwith a like panel, one connecting element being formed as a channel andthe other formed as a projection, the projection of one edge regionbeing configured to interfit within the channel of the other edge regionof a like panel to form a load bearing region capable of accommodatingloading applied to said interconnected panels, and wherein wheninterconnected, the major surfaces of the interconnected panels arealigned and generally in abutting relationship to form a substantiallycontinuous exposed surface.

The panel according to this aspect of the present invention providessignificant advantages over the plasterboard panels. The panel of theinvention with its paper covering, has a surface characteristic whichcan match that of plasterboard, yet offers significant improvements instructural properties because of the metal substrate. For example, thepanel may be load bearing, may be formed or otherwise shaped intocomplex configurations, and is able to exhibit improved thermal andacoustic insulation characteristics.

A particular advantage of the panel is that the surface of a wall formedfrom the panels can be finished to appear continuous using standardtechniques used on plasterboard walls. Such techniques include plasterrendering and the use of plaster tape.

Throughout the specification the term “paper” includes sheet materialformed from any fibrous material produced from either naturallyoccurring or synthetic fibres. The sheet material may be of unitary orcomposite construction. It also includes other types of sheet materialwhich have characteristics, in particular surface texture, which aresimilar to paper.

In a particularly preferred form, the panel of the invention is formedin continuous lengths using a laminating process to adhere the papercovering to the metal substrate. The production of panels in this wayprovides significant cost benefit and also has the advantage of enablingpanels of indefinite length to be produced.

Preferably the building panel includes a generally planar abutmentsurface at each longitudinal edge region which extends generallyperpendicular to the major surface. Preferably the connecting elementsare disposed inwardly of the major surface with the abutment surfacesbeing disposed between the major surface and the connecting elements.This arrangement is ideally suited where the paper covering gives thepanel a surface characteristic which is substantially the same as aplasterboard panel. In that arrangement, the panel is operative to forma substantially continuous exposed surface by connection of the panelwith a like panel through interfitting of respective ones of theconnecting elements, or through abutting of an edge of a plasterboardagainst a respective one of the abutment surfaces.

The profiles may be formed in the panel using any known technique suchas roll forming, folding or the like. However in a particularlypreferred form, the panels are roll formed to the desired profile. Inthis way this forming step can be easily included as an extension to thelaminating process.

Any appropriate sheet metal may be used as the substrate, such as steel,aluminium, tin or the like. In general construction, galvanised steelhas wide application as the metal substrate as it is relativelyinexpensive, has good structural properties and is corrosive resistant.The gauge of the metal substrate may be chosen depending on the requiredstructural properties of the panel. However it is envisaged that thegauge will be between 0.3 to 1 mm in most applications. Metal fallingwithin this range of thicknesses can easily be cut thereby enablingservices to be easily installed in the panel on site.

In a particularly preferred form, the panel is bonded directly to themetal surface. Preferably a reactive hot melt adhesive is used to bondthe paper to the metal substrate. An advantage of using a reactive hotmelt adhesive is that it provides high bond strength including highinitial adhesive and cohesive strength which makes it ideal forlaminating the paper directly onto the bare metal substrate. The abilityto bond the paper directly onto a metal substrate again providessignificant cost benefit in that it avoids the need for pretreatment ofthe metal such as the application of a primer coat to the metal surface.However, it is to be appreciated that intermediate layers such as paintor waterproof coatings may be included between the metal substrate andthe paper covering if required.

In a preferred form, the adhesive is applied by a roller to the metalsurface, as this gives good even coverage of the adhesive across thesubstrate surface which is important for providing an even surfacefinish on the panel.

The building panel of the invention has widespread application and canbe used instead of, or in conjunction with, traditional paneling such asplasterboard. For example, the paneling of the invention may be used asa fascia, a ceiling panel or the like. In addition it may be used inconjunction with a traditional plasterboard partition or wall. Forexample, the panel may be included in a section of a plasterboard wallwhere a complex surface, such as a curved wall, is required which couldnot be formed using conventional plasterboard.

The building panel may also incorporate additional layers to improve itsstructural properties. For example, the panel may include additionalinsulating or thermal layers bonded to the metal substrate on theopposite surface to the paper covering. Again these additional layersmay be bonded using any known technique but are preferably applied usinga laminating process so as to be easily incorporated in the overallforming process of the panel.

In a particularly preferred form, the building panel is incorporated aspart of an integrated structural or composite panel. In thisarrangement, the composite panel includes spaced sheet structures whichare interconnected by a core and wherein at least one of the sheetstructures includes a building panel as described above with the papercovering forming an outer surface of the composite panel.

A composite panel according to this arrangement has widespreadapplication for use as interior walls or partitions. The composite panelis self supporting, is able to be configured to be load bearing and canincorporate profiled edge regions to enable the panel to be interlockedwith adjacent panels.

In a preferred form, both the sheet structures of the panel are formedat least partially from a metal sheet. If only one side of the panel isto be exposed, then only the exposed face need include the covering; theother face may remain bare metal. If both sides are to be viewed thenboth faces can include the paper covering. Alternatively, if required,different surface finishes may be used. For example, one surface mayinclude a plastic or similar water impermeable covering for use in abathroom or the like while the other face may include the papercovering. If required, one face may include a decorative surface such asa timber veneer or the like.

A particular advantage of using metal sheet as part of the compositepanel is that the longitudinal edges can be formed so as to enable thepanel to interlock with adjacent panels thereby facilitating theconstruction of a wall using the structural panels. The profile of thelongitudinal edges of the composite panel may be such that no additionalfasteners are required. Alternatively, the edge profiles may be designedsolely to align the adjacent panels and mechanical fasteners such arivets, screws or inserts are used to fasten the panels together.

In one form, the panels are installed using top and bottom rails. Therails may have a simple C-shaped cross section. In this arrangement, thedepth of the rails, the distance they are spaced apart, and the heightof the panel is related so that the panels may be easily installed bymerely locating the upper end of the panel into the top rail and thenswinging the bottom end of the panel into alignment with the bottom railand then dropping the panel down into the bottom rail. The panel is thencaptured between the top and bottom rails and may be secured in place byfasteners, such as rivets or self tapping screws or the like. It is tobe appreciated that other fastening arrangements may be used. Forexample the rails may be specially formed so that they interlock withthe panels without the need for separate fasteners.

The core of the composite panel may be of any suitable form depending onits application or requirements. In particular, the core may be of solidconstruction of may be of open form including interconnecting webs tothereby form cavities within the core. These cavities may be used toreduce the weight of the integrated panel or to provide passage forservices such as wiring and the like.

In one form, the edge profiles are shaped to form a slip joint at theinterlock between the adjacent panels. In this arrangement, one edgeprofile forms the male component of the slip joint where as the edgeprofile of the other panel forms a complimentary female component of thejoint. In a particularly preferred form, the panels are arranged tointerlock in a snap fit manner so as to facilitate proper engagement ofthe panels and to resist inadvertent separation.

In another form, the edge profiles are specifically designed to form aload bearing member at the interlock between adjacent panels. In apreferred form, the interlock is still by virtue of a male/femalecoupling but the edge profiles are shaped to form a part box section.The section has inherent strength and also is convenient for use in thepassage of cabling or other services. Moreover, the male coupling may bearranged to be drawn into tight engagement with the female coupling sothat the overlapping structure of the male and female connection acts inunison thereby increasing the load bearing capability of the panels.

In one form, the composite panel is designed to be able to receive astructural member which acts as a reinforcing element between its sheetstructures. The reinforcing element improves the load bearing capabilityof the panel and preferably comprises a metal beam.

In a particularly preferred form, the edge profiles are designed to beable to receive the reinforcing element so that the reinforcing elementis contained within the connection between the adjacent panels and isfully concealed. In this way, a wall formed from the panels may becontinuous across the joint which contains the reinforcing element.

In a further arrangement, the edge profiles are formed separate to thepanel and are arranged to be located over, and secured to, the edgemargins of the panels which are typically unformed. This arrangementenables use of a composite panel with straight edges. Alternatively, theseparate edge profiles may be used as an accessory to the buildingsystem incorporating the composite panels with the profiled edges. Forexample, the edge profiles may be used when it is required to cut thecomposite panel or when the composite panel is required to interfit withconventional panels or other building members.

In a further aspect, the present invention relates to a building systemwhich has enhanced load bearing capabilities.

According to this aspect, the present invention provides a buildingsystem including a building panel and a reinforcing element, thebuilding panel having spaced metal sheets interconnected by a core, saidmetal sheets defining opposite major surfaces of said panel, each ofsaid metal sheets including opposite edge regions which formlongitudinal edge regions of the panel, wherein at least one of the edgeregions of the metal sheets on both opposite sides of the panel isprofiled to form connecting elements, the connecting elements of thelongitudinal edge regions of the panel being adapted to interfit withthe connecting element of a respective one of the longitudinal edgeregions of a like panel, the panel being configured such that the majorsurfaces of the interconnected panels are aligned and in substantiallyabutting relationship to form a substantially continuous surface andwherein the reinforcing element is operative to be installed at thejoint formed on connection of the panel with a like panel and is securedin place by locating between the interfitting connecting elements toform a concealed reinforcing element which is operative to improve theload bearing characteristics of the interconnected panels.

Preferably the sheet structures are formed of metal and at least one ofthe sheet structures may be in accordance with an earlier aspect of theinvention and incorporate a paper covering. Alternatively, the metalsheet structures may be fully exposed such as if a stainless steelsurface is required, or other finishes or composite materials may beused.

The advantage of this aspect of the invention is that it provides abuilding panel with enhanced load bearing properties as compared tosimple sandwich panels. Further, fully concealing the reinforcingelement enables continuous smooth surfaces on both sides of the panelsto be obtained.

A panel in accordance with this aspect of the invention is suitable foruse both as wall panels or ceiling or floor paneling.

In a particularly preferred form, the sheet structure includeslongitudinal edge regions which are profiled to enable the panels to beconnected in abutting relationship with a like panel in edge to edgerelationship and the reinforcing element is locatable within the jointformed at the abutting panels.

In a particularly preferred form, the panel is arranged to interlockwith a like panel at the longitudinal edge regions. Preferably thelongitudinal edge regions interlock with the reinforcing element. Thisarrangement has the advantage that if further increases the load bearingcapability of the panel as the reinforcing element and the profiledlongitudinal edge regions can work together.

It is convenient to hereinafter describe embodiments of the presentinvention with reference to the accompanying drawings. It is to beappreciated however that the particularity of the drawings and therelated description is to be understood as not limiting the precedingbroad description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings;

FIG. 1 is a perspective view of a panel according to an embodiment ofthe invention;

FIG. 1A is a detailed view to an enlarged scale illustrating theconstruction of the panel of FIG. 1;

FIG. 2 is a perspective view illustrating the panel of FIG. 1 used as aceiling panel when in position;

FIG. 3 is a perspective view of a composite panel according to anembodiment of the invention;

FIG. 3A is a detailed view to an enlarged scale illustrating theconstruction of the panel of FIG. 3;

FIG. 4 is an exploded perspective view illustrating the connection ofthe panel of FIG. 3 with a like panel;

FIG. 5 is a cross sectional view of the connection of the panel of FIG.3 with a like panel.

FIG. 6 is a perspective view illustrating the connection of a variationof the panel of FIG. 3 with a like panel and including an intermediatereinforcing element;

FIG. 7 illustrates a variation of the panel of FIG. 3 and its connectionwith a like panel;

FIG. 8 is a partial perspective view illustrating the connection of anend trim component to the panel of FIG. 7;

FIGS. 9A and 9B are schematic side views showing installation of thepanel into top and bottom rails;

FIG. 10 is a perspective view illustrating the connection of a variationof the panel of FIG. 3 with a like panel and including an intermediatereinforcing element;

FIG. 11 illustrates a variation of the panel of FIG. 3 incorporateseparately formed longitudinal edge profiles;

FIG. 12 is a partial perspective view illustrating the panel of FIG. 10when used as a flooring system; and

FIG. 13 is a line diagram of a laminating process for use in theproduction of a building panel.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a building panel 10 which is generally planar andincludes opposite major surfaces 11 and 12 interconnected by edgeregions 13 and 14.

The panel 10 is of composite material and formed from a laminatingprocess which forms the panel in continuous lengths. The panel may be ofany desired width, although if made from one sheet, the width will belimited by the width of the feed stock. In one form, the panel is formedin standard widths of 1200 mm, 900 mm, 600 mm and 300 mm.

The panel includes a metal substrate 15 and a paper covering 16 which isbonded to the substrate 15 by a reactive hot melt adhesive 17. Thecovering 16 constitutes a heavy plasterboard paper so that the outerface 11 of the panel has the same general appearance and surfacecharacteristics of a plasterboard panel. In the illustrated form, thesubstrate 15 is formed of galvanised steel thereby enabling the innersurface 12, which in use is concealed, to remain exposed due to itscorrosive resistant properties.

The edge regions 13 and 14 of the panel are profiled so as to enable thepanel 10 to be connected at these edge regions to a like panel. In theillustrated form, the profiles on the edge regions 13 and 14 are formedby roll forming the metal substrate 13. The edge regions 13 and 14 areformed with one edge region 13 forming a female coupling which isadapted to receive and contain the other edge region 14 which is formedas a male coupling. With this arrangement, the male edge region 14locates in and is retained within a seat 18 formed within the femaleedge region 13 of a like panel so that the adjacent panels can beinterconnected along their edge regions.

It is to be appreciated that the profiles formed in the edge regions 13and 14 may take different embodiments as will be appreciated to thoseskilled in the art of roll forming techniques. Specifically, theprofiles can be matched to suit the particular requirements of the paneland the mode of connection required between adjacent panels. Forinstance, the profiles may be designed such as those illustrated, to notrequire the addition of any mechanical fasteners to interconnect likepanels together. Alternatively the edge regions could be formed so as toprovide formations to receive specific mechanical fasteners such asrivets or screws or the like.

FIG. 2 illustrates the panel 10 in place as part of a ceiling with thepanel 10 aligned, and fixed to, the underside of parallel roof batons60. In the illustrated form, the batons incorporate clips which areadapted to engage and hold the edge regions 13 and 14 of the panels. Inthis arrangement, the ceiling panels are installed progressively acrossthe baton. A first panel 10 ^(i) is installed and fastened to the clips61. A second panel 10 ^(ii) is then installed by locating the male edgeregion 14 ^(ii) within the female edge region 13 ^(i) of the affixedpanel 10 ^(i) whilst the panel 10 ^(ii) is inclined relative to thefixed panel 10 ^(i). Once located in place, the panel 10 ^(ii) is thenswung up into alignment with the panel 10 ^(i) wherein its female edgeregion 13 ^(i) engages with associated clips 61 attached to the batons.The process then continues until all the panels are in place.

With this arrangement, the fixed panels 10 have respective outer faceswhich incorporate the plasterboard paper covering and thereby have ageneral appearance of plasterboard. If required, edge trim (not shown)can be inserted between the adjacent panels. Typically the panels wouldinclude a bead or similar protrusion which locates within an associatedgroove (not shown) formed in the edge regions 13 and 14 of therespective panels. Alternatively, the joint between the panels could beconcealed so that the ceiling surface is continuous using standardfinishing techniques such as plaster rendering or the like.

FIG. 3 illustrates a building panel 20 according to a second embodimentof the invention. The panel 20 is of sandwich construction incorporatingfirst and second spaced structures 21 and 22 respectively, which areinterconnected by a core 23. The panel 20 further includes edge regions24 and 25 which are profiled to enable the panel 20 to be interconnectedto a like panel.

As best illustrated in FIG. 3A, each of the sheet structures 21 and 22incorporate a structure which is similar to the panel 10 illustratedabove. Specifically the panels 21 and 22 incorporate a metal sheetsubstrate 26 which includes a covering 27 formed from heavy plasterboardpaper which is bonded to an outer surface 28 of the metal substrate 26by a reactive hot melt adhesive 29. Similarly, an inner face 30 of themetal substrate 26 is bonded to the core 23 by a similar adhesive 31.The longitudinal edge regions 24 and 25 are profiled by roll forming therespective edge regions of the metal substrates 26 of the respectivesheet structures 22 and 21.

The core 23 of the panel is illustrated as a foam block. However it isto be appreciated that the core may be formed of any suitable structuredepending on the application of the panel 20. For example, the core maybe formed from a composite construction and/or may include cavities orchannels if desired.

In a similar manner to the earlier described embodiment, the panel 20 isformed from a laminating process. Typically the sheet structures 21 and22 are formed in a first laminating process. The sheet structures thenform part of a second laminating process where they are bonded to thecore. If desired, additional layers can be bonded to the panels tofurther improve the structural properties of the panel 20. For exampleadditional layers may be incorporated to further increase the thermal oracoustic insulation properties of the panel. By virtue of the laminatingprocess, the panels 20 are formed in continuous lengths and aretypically formed in a range of standard widths such as 1200 mm, 900 mm,600 mm and 300 mm.

The panel 20 has the general appearance and surface characteristics ofplasterboard by virtue of the heavy paper covering 27. However becauseof its sandwich construction and sheet metal substrate, the panel 20 islightweight, yet is self supporting and capable of acting as a loadbearing member.

The edge region 24 of the panel 20 is roll formed to include alongitudinally extending projection 32 and recess 33 which are locatedintermediate the opposite faces 38, 39 of the panel 20. In theillustrated form, the projection 32 is formed from roll forming the edgeof the structure 21 whereas the recess is formed from roll forming theedge region of the structure 22. An abutment face 34 is located betweenthe face 38 and projection 32 and a similar abutment face 35 is formedbetween the recess 33 and the face 39.

Both the projection 32 and the recess 33 are shaped to be complementarysuch that the projection 32 is able to be received within the recess 33of a like panel. To facilitate interconnection of adjacent panels, boththe projections and the recesses include tapered surfaces to provideadequate lead in.

The other longitudinal edge region 25 of the panel 20 includes a similaredge profile and includes both a recess 32 and a projection 33, with theexception that the projection is formed from roll forming the edge ofthe sheet structure 22 whereas the recess 33 is formed from roll formingthe edge region 21.

The panel 20 is arranged to be self supporting and typically arranged tobe installed between top and bottom rails (62 63) which are formed asC-shaped channels or the like. FIGS. 9A and 9B illustrate theinstallation of the panel 20 between the rails 62 and 63. The panels areeasily installed by merely locating the upper end 51 of the panel intothe top rail 62 and then swinging the bottom end 52 into alignment withthe bottom rail 63 and then dropping the bottom panel 20 into the bottomrail. The relationship of the distance between the panels to the heightof the panel is such that the panel remains captured between the top andbottom rails as best illustrated in FIG. 9B. Once in this position, thepanels can then be interlocked with a like panel as will be described inmore detail below. Once fully in position the panel are then secured inplace to the rails merely by the use of fasteners, such as rivets orself tapping screws or the like.

FIGS. 4 and 5 illustrate the connection of the panel 20 with a likepanel. For ease of identification, one panel is designated 20 ^(i)whereas the other panel is designated 20 ^(ii). Other features of thepanels are distinguished in a similar manner.

As best illustrated in FIG. 5, the edge regions 24 ^(i) and 25 ^(ii)enable two panels 20 ^(i) 20 ^(ii) to be connected in edge to edgerelationship with the respective projections and recesses of the edgeregion 24 ^(i) engaging with the respective projections and recesses ofthe edge region 25 ^(ii) of adjacent panel 20 ^(ii). Furthermore, theabutment surfaces 34 ^(i) and 35 ^(ii) engage so as to form a simplelinear join 36 between the abutting panels 20 ^(i) and 20 ^(ii).

In the illustrated form, both the longitudinal edge regions 24 and 25 ofthe panel is slightly waisted to form a recessed portion 37 in the outersurface of both the structures 21 and 22. This recess is designed toenable the joint 36 between adjacent panels to be easily covered over byplaster tape or plaster rendering which will be applied within therecess and create a flush surface across the joint

The profile of the edge regions 24 and 25 also enables the panel 20 tobe easily used in conjunction with standard plasterboard panels.Specifically, the abutment surfaces 34 and 35 provide a space to enablea plasterboard panel to be located in abutting relationship with thepanel 20. The abutment surfaces 34 and 35 are dimentioned to be slightlylarger than a standard plasterboard panel which is typically 10 mm or 13mm, so as to provide adequate clearance for the plasterboard panel to belocated outside the projection 32 and the recess 33 so that theplasterboard surface can be flush with the respective faces 38 and 39 ofthe panel 20.

The coupling arrangement to join adjacent panels using the interfittingprojections and recesses 32 and 33 provide an area of load bearingstrength at the engaged edge regions. This has significant advantage asit improves the load bearing characteristics of the wall formed by theadjacent panels. In most applications, the interconnection of the panelsgives the wall sufficient load bearing characteristics. If, however,additional load bearing strength is required in the constructed wallusing the panels 20, a metal reinforcing element 40 may be incorporatedat the connection. One such example is illustrated in FIG. 6 where thebeam is formed from roll formed metal sheet 41 and incorporatesoppositely disposed channels 42 and 43 which are arranged to interfitbetween the engaging projections and recesses (32 and 34) of theadjacent panels 20 ^(i) and 20 ^(ii). The reinforcing element 40substantially improves the load bearing characteristics of the wall as,by virtue of its configuration and its engagement with the adjacentpanels, it is able to accommodate substantial compressive loading.

FIG. 7 illustrates a variation of the coupling arrangement betweenadjacent panels 20 ^(i) and 20 ^(ii). In this arrangement both thelongitudinal edge regions 24 and 25 incorporate a pair of recesses 33.As illustrated in FIG. 7 in connecting the panel 20 ^(i) to like panel20 ^(ii), the recesses 33 ^(i), 33 ^(ii) of the respective panels arearranged to be aligned and inserts 44 are located within the cavityformed between the aligned recesses to couple the panels together. Theinserts may be of any suitable form and may include a continuous strip45 which extends over the majority of the length of the connectedpanels, or may be in the form of smaller wedges 46 which extends overonly a portion of the length of the panels.

FIG. 8 illustrates a specially formed edge strip 50 which is arranged tobe coupled to the longitudinal edge region 24 or 25 of the panel 20. Theedge strip 50 may be solely as a decorative end strip or may have afunctional purpose such as form part of a door frame assembly as in theillustrated embodiment where the strip 50 is configured to form a doorjamb.

FIG. 10 illustrates a further variation of the panel 20. This panelincludes many similar features to the earlier embodiments andaccordingly like reference numerals have been given to like features. Ina similar arrangement to the previous embodiments, the panel 20 includeslongitudinal edge regions 24, 25 which are profiled to enable the panel20 to interlock with a like panel. A reinforcing element 40 is alsoarranged to interfit at the joint between adjacent panels.

In the illustrated form, the longitudinal edge region 24 provides a pairof recesses or female couplings 33 whereas the edge regions 25 provide apair of male couplings or projections 32. It is to be appreciated thatif desired, each edge region could include both a male and femalecoupling similar to that illustrated in FIG. 3.

In the embodiment of FIG. 10, the profiles have been specificallydesigned to give the panel enhanced load bearing characteristics at itsjoint with an adjacent panel. The male and female couplings are shapedto provide generally a part box section which interlocks with a snap fitaction. This arrangement has the advantage that the box section providesgood load bearing characteristics and the snap fit action draws theinterlocking members together. This inhibits inadvertent separation ofthe members and also enables the interlocking panels to act as a singleunit thereby enhancing the panels overall load bearing capabilities atthis connection.

The male coupling 32 includes opposite walls 53 and 54 which areinterconnected by a base portion 55. To provide the snap fit, the walls53 and 54 are not linear but rather includes outwardly extending crests56 intermediate the ends of the respective walls 53, 54. The femalecoupling 33 incorporates a complimentary shaped recess. Specifically,the female coupling 33 incorporates opposite walls 57, 58 which areinterconnected by base portion 59 and which incorporate re-entrantportions 64 on their inner surface. In use, on interconnecting thepanels together the male and female couplings are caused to flex throughengagement of the male coupling walls 53, 54 with the female couplingwalls 57, 58. The flexing continues until the crests 56 begin to alignwith the re-entrant surfaces 64 whereafter the couplings begin to returnto their natural state as the crests move into alignment with thereentrant surfaces 64. Once in alignment, the resilience of thecouplings inhibits the release of the two interconnected members.

The positive or snap fit between the male and female couplings occurswhether or not the reinforcing element 40 is incorporated. The profileof the reinforcing element 40 has inner surfaces 65 which matches thatof the female couplings 33 and an outer surface 66 which matches that ofthe male coupling 32. As a result, the reinforcing element 40 is able tosnap fit into connection with the female couplings 33 ^(i) of a firstpanel 20 ^(i). Once in place, the male couplings 32 ^(ii) of the likepanel 20 ^(ii) is then able to locate into engagement with the innersurface 65 of the connected reinforcing element 40.

FIG. 11 illustrates a similar view to that illustrated in FIG. 10 exceptthat the edge profiles 24,25 are formed separately to the panel 20. Inthis arrangement the edge profiles 67, 68 are similar to the edge strip50 are formed from a folded metal sheet and are secured to the edgemargins of the panels using any suitable fastening arrangements such asby screw, adhesive or the like. These edge profiles 67, 68 enable thesystem to be used with a panel 20 having a straight edge and may be usedwhen it is required to cut the structural panel or when the structuralpanel is required to interfit with conventional panels or other buildingmaterials.

The composite panel 20 incorporating the profiled edges and the internalreinforcing element 40 may be advantageously used in many aspects ofbuilding constructions including in interior as well as exterior wallstructures, or in flooring or ceiling systems. Further, the choice ofthe surface materials used to form the outer faces 38, 39 of the panelwill depend on the application of the panel. For example, if the panelis to be used as an internal partition wall, then the paper covering maybe laminated to the metal substrate as described earlier so that thepanel has a surface characteristic which is similar to that ofplasterboard. Alternatively, the outer face of the panel may be exposedmetal, such as stainless steel, which is suitable for use in operatingtheatres or the like. In this example, to reduce material cost, thestainless steel may be applied as a laminate to the metal substrate ofthe panel 20 or alternatively the substrate may be formed from solidstainless steel. It is to be appreciated that other surfaceconfigurations could be used as will be appreciated by those skilled inthe art.

FIG. 12 illustrates a further variation of the panel when used as partof a flooring system. In this arrangement the reinforcing element 40acts as an internal bearer thereby providing the required loadingcharacteristics for the flooring system. In this arrangement the upperface 38 incorporates a timber veneer so as to give the impression of atimber floor.

FIG. 13 illustrates a line diagram of a laminating process used to bondthe paper covering to the metal substrate for use in the building panelof the invention.

In this process, the metal feed stock 26 which is typically galvanisedsteel but may be any other sheet metal, is fed from an uncoiler 101 intothe process line 100. The sheet metal is then correctly positioned byrunning through an edge guide 102 and then subsequently through astraightener 103. The sheet metal then passes through a cleaning andheating unit to remove any debris on the metal surface and to bring thetemperature up to a predetermined level. The exact temperature rangeused is dependent on the characteristics of the adhesive being appliedbut is typically in the range of 20 to 50° C. The sheet metal thenpasses through to an adhesive coater 105 which incorporates a roller 106which comes into contact with the upper surface 28 of metal substrate 26so as to apply a thin film to the metal sheet. The adhesive is areactive hot melt polyurethane and is typically applied at a temperaturein the range of typically 110 to 140° C. with a coating being applied tothe metal surface in the order of 10-20 microns in thickness.

After the adhesive has been applied, the metal sheet 26 then passesthrough a humidifier 107 which further conditions the adhesive coatingon the metal surface 28. The sheet then passes to a laminator 108 wherethe paper 27 which is stored in a coil 109 is applied under tension tothe surface 28 of the metal 26. The laminated product is then fed to arecoiler wherein it is stored in rolls ready for transporting (asillustrated) or to a further production station. The station furtherprocesses the metal panel and may include a roll forming station to formthe edge profiles, a sheering station to form the panel into sheet formor to slit the metal panel so as to alter the panel width. To make theintegrated composite building panel 20, the laminated metal sheet is fedto separate laminating process to form the panel 20 with its sandwichconstruction.

An advantage of the panel of the present invention is that the paperlaminated metal sheet is inexpensive to manufacture as it can be madeusing the laminating process without requiring any pretreatment, such aspainting of the metal substrate. This has substantial practical benefitas it enables the building panel formed from the metal substrate to beextremely competitive in price with traditional plasterboard panels.Furthermore by making the building panel using the composite material ofa metal sheet substrate and a paper covering, the panel of the inventioncan be used in conjunction with plasterboard panels, as it has a surfacecharacteristic which can match that of plasterboard, yet has theadditional advantages in that it can be load bearing, can be formed orotherwise shaped into complex configurations, including being able tohave profiled edges to enable the panel to be interlocked with a likepanel and can be designed to have improved thermal and acousticinsulation characteristics.

Finally it is to be understood that modifications and or additions maybe made to the parts as previously described without departing from thespirit or ambit of the invention.

What is claimed is:
 1. A building panel of sandwich constructioncomprising a core and spaced metal sheets fixed to opposite major facesof said core, said core including opposite end edges which extendbetween said opposite major faces thereof, said panel having oppositemajor surfaces and opposite longitudinal edge regions, each of saidmetal sheets comprising opposite edge regions which form thelongitudinal edge regions of the panel and which extend inwardly of saidopposite major surfaces of said panel to form a pair of connectingelements at each edge region of the panel, said connecting elementsextending across the end edges of said core and being formed as either achannel or a projection, the connecting elements of the longitudinaledge regions of the panel being adapted to interfit with the connectingelements of a respective one of the longitudinal edge regions of anotherpanel to provide for interconnection of the panel with another panel andto form a load bearing region capable of accommodating loading appliedto the interconnected panels, wherein at least one of said metal sheetshas a paper covering bonded thereto so that said metal sheet forms oneof the major surfaces of the panel, wherein the paper covering providesa surface characteristic that enables said major surfaces of the panelto be finished to appear continuous by using finishing techniques,wherein the panel is configured such that the major surfaces of theinterconnected panels incorporating the paper covering are aligned andin substantially abutting relationship to form a continuous surface,wherein said finishing techniques are applied to the major surfaces ofthe interconnected panels.
 2. A building panel according to claim 1,further comprising a generally planar abutment surface at eachlongitudinal edge region, the abutment surface extending generallyperpendicular to said major surfaces of said panel and wherein theconnecting elements are disposed inwardly of the at least one majorsurface of the panel having the paper covering with said abutmentsurfaces being disposed between said major surface and said connectingelements, wherein the paper covering gives the panel a surfacecharacteristic which is substantially the same as a plasterboard paneland wherein, in use, the panel is operative to form an exposed surfaceby connection of the panel with another panel through interfitting ofrespective ones of the connecting elements, or by abutment of an edge ofa plasterboard panel against a respective one of said abutment surfaces.3. A building panel according to claim 1, wherein said channel isgenerally C shaped in cross section incorporating opposite wallsinterconnected by a substantially flat base portion.
 4. A building panelaccording to claim 3, wherein the angle between the opposite walls andthe base portion is approximately 90° so that the channel forms a partbox section.
 5. A building panel according to claim 1, wherein theprojection interfits in nesting engagement within the channel of saidanother panel.
 6. A building panel according to claim 1, wherein theprojection has an outer surface which is complementary to the innersurface of the channel so that on interconnection of the panels, theprojection is in engagement with substantially all of the inner surfaceof the channel of said another panel.
 7. A building panel according toclaim 1, wherein the projection is operative to interfit with a channelof said another panel in a snap fit arrangement.
 8. A building panel ofsandwich construction comprising a core and spaced metal sheets fixed toopposite major faces of said core, said core including opposite endedges which extend between said opposite major faces thereof, said panelhaving opposite major surfaces and opposite longitudinal edge regions,each of said metal sheets comprising opposite edge regions which formthe longitudinal edge regions of the panel and which extend inwardly ofsaid opposite major surfaces of said panel to form a pair of connectingelements at each edge region of the panel, said connecting elementsextending across the end edges of said core and being formed as either achannel or a projection, the connecting elements of the longitudinaledge regions of the panel being adapted to interfit with the connectingelements of a respective one of the longitudinal edge regions of anotherpanel to provide for interconnection of the panel with another panel andto form a load bearing region capable of accommodating loading appliedto the interconnected panels, wherein at least one of said metal sheetshas a paper covering bonded thereto so that said metal sheet forms oneof the major surfaces of the panel, wherein the paper covering providesa surface characteristic that enables said major surfaces of the panelto be finished to appear continuous by using finishing techniques,wherein the panel is configured such that the major surfaces of theinterconnected panels incorporating the paper covering are aligned andin substantially abutting relationship to form a continuous surface,wherein said finishing techniques are applied to the major surfaces ofthe interconnected panels, wherein the projection is operative tointerfit with a channel of said another panel in a snap fit arrangement,wherein the channel includes a re-entrant portion on its inner surface,and wherein the projection includes a crest portion on its outer surfaceand wherein the crest portion on the projection of one panel is arrangedto engage with the re-entrant portion of the channel of said anotherpanel in a snap fit arrangement.
 9. A building panel according to claim1, wherein the edge region of the major surface of the panelincorporates a recess to facilitate concealment of a joint between thepanel and said another panel by using finishing techniques.
 10. Abuilding panel according to claim 1, wherein said paper is bonded tosaid substrate using a reactive hot melt adhesive.
 11. A building panelaccording to claim 1, wherein said paper is bonded directly onto saidmetal substrate.
 12. A building panel according to claim 1, wherein themetal, substrate is selected from the group consisting of mild steel,aluminum, tin, stainless steel, and galvanized steel.
 13. A buildingpanel according to claim 1, wherein the gauge of the metal substrate isbetween 0.3 to 1 mm.
 14. A building system including a building paneland a separate reinforcing element, the building panel comprising a coreand having spaced metal sheets fixed to opposite major faces of saidcore, said core including opposite end edges which extend between saidopposite major faces thereof, said panel having opposite major surfacesand longitudinal edge regions, said metal sheets including opposite edgeregions which form longitudinal edge regions of the panel, wherein saidedge regions extend inwardly of said opposite major surfaces of saidpanel and across each end edge of said core to provide forinterconnection of the panel with another panel and to form a loadbearing region capable of accommodating loading applied tointerconnected panels, and each edge region of the panel is profiled toform a pair of connecting elements which extend across the end edges ofsaid core, the connecting elements of the longitudinal edge regions ofthe panel being adapted to interfit with the connecting element of arespective one of the longitudinal edge regions of another panel, eachconnecting element being formed as either a channel or a projectionwhich cooperate to interfit, each channel incorporating opposite wallsinterconnected by a substantially flat base portion, and wherein eachprojection is shaped to interfit with the channel of said another paneland includes opposite walls interconnected by a substantially flatbridging portion, the panel being configured such that the majorsurfaces of the interconnected panels are aligned and in substantiallyabutting relationship to form a substantially continuous surface andwherein the reinforcing element is operative to be installed at a jointformed on connection of the panel with said another panel and is securedin place by locating said reinforcing element between and in connectionwith the interfitting connecting elements of each panel to conceal thereinforcing element which is operative to improve the load bearingcharacteristics of the interconnected panels and wherein saidreinforcing element includes at least one engagement part which isgenerally U-shaped and located between said interfitting channel andprojection of the interconnected panels.
 15. A building system accordingto claim 14, wherein the reinforcing element includes spaced apartengagement parts interconnected by a web.
 16. A building systemaccording to claim 14, wherein the angle between the opposite walls ofeach channel and the base portion is approximately 90° to form a partbox section.
 17. A building system according to claim 14, wherein theangle between the opposite walls of each projection and the bridgingportion is approximately 90° to form a part box section.
 18. A buildingsystem according to claim 14, wherein the opposite walls of each channelinclude a re-entrant inner surface, and wherein the outer surface of theopposite walls of each projection include a crest and wherein the crestportion on the projection of one panel is arranged to engage with there-entrant inner portion of the channel of said another panel in a snapfit arrangement.
 19. A building system according to claim 14, whereinthe connecting elements are adapted to interfit with the connectingelements of said another panel and with the reinforcing elements in asnap fit arrangement.
 20. A building system according to claim 14,wherein the building panel further includes at least one abutmentsurface at each longitudinal edge region, the at least one abutmentsurface extending generally perpendicular to said major surfaces of saidpanel and is disposed between a respective one of the major surfaces andsaid connecting elements.
 21. A building system according to claim 14,wherein a paper covering is bonded to at least one of the metal sheetsso that said paper covered metal sheet forms one of the major surfacesof the panel.
 22. A building system according to claim 21, wherein saidpaper is bonded to said metal sheet using a reactive hot metal adhesive.23. A building system according to claim 21, wherein said paper isbonded directly onto said metal sheet.
 24. A building system accordingto claim 21, wherein the metal sheet incorporating the paper covering isformed in continuous lengths using a laminating process to adhere thepaper covering to said metal sheet.
 25. A building panel comprising ametal sheet substrate and a paper covering bonded to said substrate,wherein said paper covered metal sheet forms a major surface of thepanel with the paper covering providing a surface characteristic to thatmajor surface that is structured to be finished using conventionalfinishing techniques, and wherein said metal sheet includes oppositeedges which are shaped to form edge regions of the panel, each edgeregion being formed to include a connecting element which extends alongthat edge region and which allows for interconnection of the panel withanother panel, and wherein when interconnected, the major surfaces ofthe interconnected panels are aligned and in substantially abuttingrelationship to enable a continuous surface to be obtained on applyingthe conventional finishing techniques to the paper covered majorsurfaces of the interconnected panels.
 26. A building panel according toclaim 25, wherein one connecting element is formed as a channel and theother formed as a projection, the projection at one edge region beingconfigured to interfit within the channel of the other edge region ofsaid another panel to form to a load bearing region capable ofaccommodating loading applied to the interconnected panels.
 27. Abuilding panel according to claim 8, wherein the connecting elements ofthe panel are sufficiently resilient so that the projection and channelare drawn into engagement on interconnecting of the panel with anotherpanel in the snap fit arrangement through interengagement of the crestand re-entrant portions.
 28. A method of building a partition having acontinuous surface comprising the steps of: providing a plurality ofpanels, each panel comprising a metal sheet substrate and a papercovering bonded to said substrate, said paper covered metal sheetforming a major surface of the panel with the paper covering providing asurface characteristic to that major surface that is structured to befinished using conventional finishing techniques; interconnecting thepanels so that the major surfaces of the interconnected panels arealigned and in substantially abutting relationship; and applying thefinishing techniques to the paper covered major surfaces of theinterconnected panels to form a continuous surface across theinterconnected panels.
 29. A method according to claim 28, furthercomprising the step of: forming a load bearing region at the jointbetween the interconnected panels, the load bearing region being capableof accommodating loading applied to the interconnected panels.
 30. Amethod according to claim 29, further comprising the step of: locating areinforcing element within the joint between adjacent panels to increasethe load bearing capacity of the load bearing region.
 31. A methodaccording to claim 28, wherein the panels are interconnected byinterfitting of a projection formed on one panel within a channel formedin the other panel.
 32. A method according to claim 28, wherein plasterbased finishing techniques are applied to the interconnected panels toform the continuous surface.